Federal officials are trying to determine if a recent inspection of the de-icing equipment on the plane that crashed outside Buffalo last week was routine – or the result of a problem.

National Transportation Safety Board prober Steve Chealander told a press conference the de-icing equipment was checked after a flight not long before last Thursday’s fiery crash, which killed 50 people.

Chealander also disclosed that less than a half-hour after the crash, another Continental flight flew the same route from Newark to Buffalo in the same model turboprop and landed safely.

He said probers have located key parts of the doomed aircraft that might show what the pilot did to try to save it during Flight 3407’s final, desperate seconds, when it plunged so suddenly, that sending a mayday was impossible.

They have located the steering column, or yoke; all the propeller blades; five of six deicing valves; and rubber bladders designed to expand and crack the ice off the tail, Chealander said.

The turboprop – operated by Colgan Air for Continental – had been flying on autopilot as ice built up on its wings and windshield, until just 26 seconds before it went down.

Chealander criticized his sister agency – the Federal Aviation Administration – for years of blowing off more than 50 NTSB safety recommendations. Three of them, involving autopilots and icing, relate to the tragic flight.

The NTSB wants the FAA to prohibit the use of autopilots whenever ice is forming. But the FAA, which sets the rules, has been ignoring the proposal for eight years and continues to ban autopilots only when icing is “severe.” The FAA is checking with other pilots who had been flying in the area last Thursday to gauge the severity of the icing.

Another measure would require retesting all turboprops like the model that went down to make certain they can handle icing.

The third recommendation would give pilots more warnings when an autopilot shuts down automatically.

The autopilot on the ill-fated plane disengaged when the craft started making wild rolling and pitching movements. The pilots were alerted that it had been turned off by a safety mechanism that caused the steering column to shake.

In 1998, the NTSB asked the FAA to mandate that autopilot systems set off an audible alarm and light up an amber warning signal when they disengage.

Chealander raised the possibility that when the yoke started shaking, the pilot overreacted by yanking it back, further destabilizing the plane.

The NTSB also wants pilots of planes such as the Bombardier Dash 8 that went down to turn on their de-icing equipment as soon as they enter icing conditions.

The doomed pilots apparently knew that – they activated their de-icers 11 minutes after they took off.

Meanwhile, it was learned that the pilot in command, Marvin Renslow, worked as a part-time produce stocker.

He began as a reservation attendant with now-defunct Piedmont Airlines, said his brother, Melvin Renslow. Eventually, he said, his brother wanted a career change.

He learned how to fly at a private school and eventually signed up with Colgan.

To supplement his salary, he moonlighted in the Tampa, Fla., market, employees said.